"""schema definition related entities

:organization: Logilab

:copyright: 2001-2010 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

:license: GNU Lesser General Public License, v2.1 - http://www.gnu.org/licenses

"""

__docformat__ = "restructuredtext en"

from logilab.common.decorators import cached

from cubicweb import ValidationError

from cubicweb.schema import ERQLExpression, RRQLExpression

from cubicweb.entities import AnyEntity, fetch_config

class CWEType(AnyEntity):

    __regid__ = 'CWEType'

    fetch_attrs, fetch_order = fetch_config(['name'])

    def dc_title(self):

        return u'%s (%s)' % (self.name, self._cw._(self.name))

    def dc_long_title(self):

        stereotypes = []

        _ = self._cw._

        if self.final:

            stereotypes.append(_('final'))

        if stereotypes:

            return u'%s <<%s>>' % (self.dc_title(), ', '.join(stereotypes))

        return self.dc_title()

    def db_key_name(self):

        """XXX goa specific"""

        return self.get('name')

class CWRType(AnyEntity):

    __regid__ = 'CWRType'

    fetch_attrs, fetch_order = fetch_config(['name'])

    def dc_title(self):

        return u'%s (%s)' % (self.name, self._cw._(self.name))

    def dc_long_title(self):

        stereotypes = []

        _ = self._cw._

        if self.symmetric:

            stereotypes.append(_('symmetric'))

        if self.inlined:

            stereotypes.append(_('inlined'))

        if self.final:

            stereotypes.append(_('final'))

        if stereotypes:

            return u'%s <<%s>>' % (self.dc_title(), ', '.join(stereotypes))

        return self.dc_title()

    def inlined_changed(self, inlined):

        """check inlining is necessary and possible:

        * return False if nothing has changed

        * raise ValidationError if inlining is'nt possible

        * eventually return True

        """

        rschema = self._cw.vreg.schema.rschema(self.name)

        if inlined == rschema.inlined:

            return False

        if inlined:

            # don't use the persistent schema, we may miss cardinality changes

            # in the same transaction

            for rdef in self.reverse_relation_type:

                card = rdef.cardinality[0]

                if not card in '?1':

                    rtype = self.name

                    stype = rdef.stype

                    otype = rdef.otype

                    msg = self._cw._("can't set inlined=%(inlined)s, "

                                     "%(stype)s %(rtype)s %(otype)s "

                                     "has cardinality=%(card)s")

                    raise ValidationError(self.eid, {'inlined': msg % locals()})

        return True

    def db_key_name(self):

        """XXX goa specific"""

        return self.get('name')

class CWRelation(AnyEntity):

    __regid__ = 'CWRelation'

    fetch_attrs = fetch_config(['cardinality'])[0]

    def dc_title(self):

        return u'%s %s %s' % (

            self.from_entity[0].name,

            self.relation_type[0].name,

            self.to_entity[0].name)

    def dc_long_title(self):

        card = self.cardinality

        scard, ocard = u'', u''

        if card[0] != '1':

            scard = '[%s]' % card[0]

        if card[1] != '1':

            ocard = '[%s]' % card[1]

        return u'%s %s%s%s %s' % (

            self.from_entity[0].name,

            scard, self.relation_type[0].name, ocard,

            self.to_entity[0].name)

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        if self.relation_type:

            return self.relation_type[0].rest_path(), {}

        return super(CWRelation, self).after_deletion_path()

    @property

    def rtype(self):

        return self.relation_type[0]

    @property

    def stype(self):

        return self.from_entity[0]

    @property

    def otype(self):

        return self.to_entity[0]

class CWAttribute(CWRelation):

    __regid__ = 'CWAttribute'

    def dc_long_title(self):

        card = self.cardinality

        scard = u''

        if card[0] == '1':

            scard = '+'

        return u'%s %s%s %s' % (

            self.from_entity[0].name,

            scard, self.relation_type[0].name,

            self.to_entity[0].name)

class CWConstraint(AnyEntity):

    __regid__ = 'CWConstraint'

    fetch_attrs, fetch_order = fetch_config(['value'])

    def dc_title(self):

        return '%s(%s)' % (self.cstrtype[0].name, self.value or u'')

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        if self.reverse_constrained_by:

            return self.reverse_constrained_by[0].rest_path(), {}

        return super(CWConstraint, self).after_deletion_path()

    @property

    def type(self):

        return self.cstrtype[0].name

class RQLExpression(AnyEntity):

    __regid__ = 'RQLExpression'

    fetch_attrs, fetch_order = fetch_config(['exprtype', 'mainvars', 'expression'])

    def dc_title(self):

        return '%s(%s)' % (self.exprtype, self.expression or u'')

    @property

    def expression_of(self):

        for rel in ('read_permission', 'add_permission', 'delete_permission',

                    'update_permission', 'condition'):

            values = getattr(self, 'reverse_%s' % rel)

            if values:

                return values[0]

    @cached

    def _rqlexpr(self):

        if self.exprtype == 'ERQLExpression':

            return ERQLExpression(self.expression, self.mainvars, self.eid)

        #if self.exprtype == 'RRQLExpression':

        return RRQLExpression(self.expression, self.mainvars, self.eid)

    def check_expression(self, *args, **kwargs):

        return self._rqlexpr().check(*args, **kwargs)

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        if self.expression_of:

            return self.expression_of.rest_path(), {}

        return super(RQLExpression, self).after_deletion_path()

class CWPermission(AnyEntity):

    __regid__ = 'CWPermission'

    fetch_attrs, fetch_order = fetch_config(['name', 'label'])

    def dc_title(self):

        if self.label:

            return '%s (%s)' % (self._cw._(self.name), self.label)

        return self._cw._(self.name)

    def after_deletion_path(self):

        """return (path, parameters) which should be used as redirect

        information when this entity is being deleted

        """

        permissionof = getattr(self, 'reverse_require_permission', ())

        if len(permissionof) == 1:

            return permissionof[0].rest_path(), {}

        return super(CWPermission, self).after_deletion_path()